Suspended luminaire assemblies typically include, among other components, an optical assembly which is typically formed of glass or plastic; an electrical assembly having a housing generally formed of metal for storing electrical components within; and a hanger member for suspending the luminaire from its intended overhead location. In order to protect these individual luminaire components, they are typically assembled, packaged, and shipped separately from each other from the point of manufacturing to the customer. This separation of components is done to reduce the risk of shipping damage caused by packaging an electrical component in the same container as a lighter or more fragile optical member. However, not only does this make the shipping and packaging process more costly and labor intensive for the manufacturer, it also increases expense for the customer at the installation site who must identify the various packages in order to find mating components, and then properly assemble and install these components in order to provide the desired lighting distribution. To complete these tasks, the installer often consults references for instruction. Moreover, the customer must often attach the hanger member to the electrical assembly and suspend it from the ceiling before installing the optical assembly to the rest of the luminaire assembly.
Further, most luminaire assemblies are assembled according to a customer specification so they may produce a desired light distribution. Such a customer specification typically requires coordinating and controlling the relative orientation of the electrical assembly with the optical assembly, which are attached via adjustable bracketry. Particularly, the lamp socket typically has a specific orientation relative to the optical assembly. Adjustments to this orientation often involve removing and reassembling multiple fasteners, repositioning and aligning brackets, and otherwise adjusting the relative positions of the electrical assembly, the socket and the optical assembly until the desired light distribution is achieved. All of these tasks are costly in terms of the great time and labor expended to accomplish them. Further, if these tasks are not performed properly, then the desired lighting distribution will not be achieved.
Moreover, because many indoor luminaire assemblies include a high intensity discharge (HID) lamp which produces a relatively large amount of heat, it may have an undesirable effect on the electrical assembly which contains heat sensitive electrical components, such as the capacitor. Portions of the lamp may reach temperatures of 1100.degree. C. On the other hand, the ballast, capacitor, relay, starters and other electrical components found in a luminaire typically produce a relatively small amount of heat when compared to the lamp. For example, a typical capacitor has a maximum operating temperature of 90.degree. C. Since the lamp is typically disposed in the socket which is oriented below and in close proximity to the electrical assembly housing, heat may be transferred from the lamp to the heat-sensitive electrical components contained in the housing.
In addition, while many luminaires have an open optical assembly (i.e., no barrier provided at the bottom), other luminaires are enclosed and have a bottom closure including a glass or plastic barrier (roundel) which is mounted to the optical assembly via a bezel or door, and often have a hinge or latch so that access to the lamp may be made convenient. The roundel provides a physical barrier between the lamp and the environment while permitting light to pass through. As with the other components, many enclosed luminaires are supplied to the customer with a bottom closure which must be attached to the optical member at the job site. Not only does this involve still more assembly cost and time by the customer, but the bezel may interfere with or block light distribution and reduce light efficiency. A typical bottom closure may also make replacing the lamp difficult.
Lastly, the aforementioned metal housing of the luminaire assembly is sometimes underutilized, and only used to contain and provide a mountable surface for the electrical components.
Consequently, there is a need for an improved luminaire assembly having reduced manufacturing, packaging and shipping costs and time for the manufacturer, as well reduced assembly, installation and labor cost and time for the customer. Further, the improved luminaire should have an electrical assembly and an optical assembly which assembly, install, and provide desired lighting distribution with minimal or no effort. The improved indoor luminaire assembly should also improve thermal isolation and reduce or eliminate the heat generated by the lamp from being transferred to the electrical components. The improved luminaire should also provide for an enclosed optical assembly which is less expensive for the manufacturer and for the customer to install. Further, the improved luminaire assembly should include an electrical assembly housing which may serve other desirable functions.